In which region of the globe did the spread of diseases though the columbian exchange drastically reduce populations?

The Americas.

Apex : 3

The discovery of the New world set in motion many changes. For example, 50 years after Columbus had arrived in the Caribbean 90% of the native population of the island Hispanola were dead from smallpox. Many diseases came from animals. Cows brought tuberculosis to American continent and from horses and pigs native Indians got influenza. The result was that those diseases drastically reduced populations in America. Answer: America.